(1) Field of the Invention
This invention relates to a process for preparing styrene by oxidative dehydrogenation of 4-vinylcyclohexene in a gaseous phase in the presence of a novel catalyst. More particularly, the invention relates to a process for preparing styrene by oxidative dehydrogenation of 4-vinylcyclohexene by contacting it with oxygen or an oxygen-containing gas in a gaseous phase in the presence of a catalyst which is essentially composed of tin, antimony and oxygen.
(2) Description of the Prior Art
It is known that styrene is produced by oxidative dehydrogenation of 4-vinylcyclohexene in the presence of a catalyst. As the catalysts used for this reaction, there have been proposed the following for instance: palladium oxide catalysts (U.S. Pat. No. 3,502,736), supported palladium catalysts (Japanese Pat. Laid-Open No. 133236/76), platinum metal catalysts (Japanese Pat. Pub. No. 8367/67), molybdenum-bismuth-oxygen catalysts (Japanese Pat. Laid-Open No. 52139/76) and catalysts containing oxides of at least one metal selected from copper, zinc, arsenic, antimony, chromium, iron and cobalt (Japanese Pat. Pub. No. 9168/70).
The present inventors have pursued further researches for a catalyst more effective for the oxidative dehydrogenation of 4-vinylcyclohexene and found out as a result that a catalyst comprising as essential constituents tin, antimony and oxygen shows high activity and selectivity in the preparation of styrene from 4-vinylcyclohexene and is capable of producing styrene in a high yield. This invention was attained on the basis of such finding.